Keywords: water splitting, carbon modified, titanium oxide, iron oxide, solar hydrogen production, nanotechnology, thin films, photoconversion efficiencies
Efficient photoelectrochemical splitting of water to H2 and O2 at nanocrystalline carbon modified (CM)-n-TiO2 and (CM)-n-Fe2O3 thin films
Carbon modified titanium oxide (CM-n-TiO2) and iron (III) oxide (CM-n-Fe2O3) thin films were synthesised by thermal flame oxidation of Ti and Fe metal sheets, respectively. Under white light illumination of intensity of 100 mW cm−2 from a 150 W xenon lamp, the optimised CM-n-TiO2 and CM-n-Fe2O3 photoelectrode were found to split water to H2 and O2 with maximum photoconversion efficiencies of 14.04% and 6.5%, respectively. The maximum photoconversion efficiencies obtained from wavelength dependent monochromatic photocurrents were found to be 13.79% and 5.9% for CM-n-TiO2 and CM-n-Fe2O3, respectively, under the same illumination intensity from the xenon lamp. Importantly, under natural global AM 1.5 sunlight illumination of 1 sun, the maximum photoconversion efficiencies for water splitting were found to be 12.26% for CM-n-TiO2 and of 5.1% for CM-n-Fe2O3.